1. Field of the Invention
The present invention relates to a storage controller and a duplicate data detection method that uses the storage controller.
2. Description of the Related Art
Companies and the like use relatively large-scale storage controllers to manage increasingly larger amounts of data. As such a storage controller, a device that is configured to enable the DMA (Direct Memory Access) transfer of data between channel adapters, memory adapters and processor adapters is known (JP-A-2005-228245).
A storage controller also manages large amounts of duplicated data. Duplicated data, for example, is data the contents of which are exactly the same, such as an original file and a copy file. Large amounts of duplicated data result in the wasteful use of the storage areas of the storage controller, increasing the operating costs of the storage controller. Further, large amounts of duplicated data make it difficult for a user to quickly access needed data. Accordingly, technology designed to determine whether or not data is duplicated data based on hash values, and to only store data that is not duplicated data has been proposed (JP-A-2007-305122).
The prior art disclosed in the above-mentioned second Patent Document (JP-A-2007-305122) removes duplicated data on the basis of hash values. However, in this prior art, a microprocessor compares data by reading comparison-targeted data into a local memory inside the microprocessor. Since the microprocessor is respectively used to detect duplicated data and to remove duplicated data, the response performance of the storage controller deteriorates.